There are more than hundred commercially available primary plasticizers for polyvinylchloride. The polyvinylchloride plasticizer must act as a solvent for the crystalline part of the polyvinylchloride at flexible processing temperatures but not at lower temperatures. The plasticizer must not react with polyvinylchloride. The plasticizers are mainly esters. Phthalates are widely used in plastics and rubber around the world, but in the late nineties health issues such as abnormalities in physiological development were noticed. Thus; phthalate-free articles are mandatory for medical devices, toys, child-care articles and food packaging.
U.S. Pat. No. 2,615,159 (referred to herein as '159 patent, assigned to M/s The Procter & Gamble Company) discloses preparation of 1-stearyl-2,3-diacetin as a novel waxy, stable, translucent solid and similar compounds for use in food preparations such as candy coating.
U.S. Pat. No. 3,748,265 (referred to herein as '265 patent, assigned to M/s Dynamit Nobel Aktiengesellschaft) teaches preparation of oxidation resistant diacetyl monododecanoyl triglyceride and its mixtures with diacetyl monotetradecanoyl or diacetyl monohexadecanoyl triglycerides. The '265 patent does not teach bio based plasticizer with improved properties and/or processing characteristics.
European patent no. 1624014B1 (referred to herein as '014 patent, assigned to M/s Danisco A/S) relates to a process for the preparation of a novel plasticizer, compound of formula
wherein at least one of R1, R2 and R3 is a branched chain acyl group with a hydrophilic branch group wherein the hydrophilic branch group is an acyl group or a derivative thereof.
Polymer Testing 32 (2013) 272-278 suggests use of vegetable based plasticizer, fully acetylated glycerol monoester based on coconut oil (Acetem) comprising a mixture of caprylic (C8), capric (C10) and lauric acid (C12) when used in polyvinylchloride films showed better mechanical performance and high transparency.
U.S. Pat. No. 4,426,477 (referred to herein as '477 patent, assigned to M/s Riken Vitamin Co. Ltd.) teaches use of a mixture of glycerin diacetate mono C10-14 fatty acid content as a plasticizer in PVC.
All the above publications do not suggest improved properties of plasticizer such as substitution factor, plasticizing efficiency or overall migration. Further, there is no suggestion of improvement in processing characteristics such as hardness, flexibility at lower temperature, fusion time or torque which play an important role in polymer processing.
Several alternatives of vegetable origin based plasticizers have been developed with the view to substitute phthalates. In view of the same we have developed a bio based plasticizer with improved properties and processing characteristic which enables ease in polymer processing.